Synthesis, Characterization, Modeling and Applications of Functional Porous Materials: Porous Materials IV
Sponsored by: ACerS Basic Science Division
Program Organizers: Lan Li, Boise State University; Winnie Wong-Ng, National Institute of Standards and Technology; Kevin Huang, University of South Carolina
Wednesday 2:00 PM
October 12, 2022
Room: 334
Location: David L. Lawrence Convention Center
Session Chair: Lan Li, Boise State University
2:00 PM Invited
Hybrid Pore Formation in Microporous Cu Spheres: Mark Atwater1; Braden Jones1; 1Liberty University
Using unique processing, we create millimeter-sized copper spheres with micron and sub-micron pores by a combination of entrapped argon and the reduction of oxide particles. This allows multi-stage foaming to be applied such that either mostly closed or open porosity can be created through choice of annealing environment. These spheres are formed through planetary ball milling of Cu and CuO, which results in a refined microstructure that is partially stabilized at elevated temperature by CuO particles and the existence of small pores before annealing. During annealing, the individual spheres, or components made from them, become highly porous throughout and able to achieve hierarchical porosity. This system serves as a template for other hybrid foaming strategies and lends particular insight into the microstructural development of these materials as well as their bulk mechanical properties. The importance of the chemistry-structure-process-property relationships will be emphasized.
2:20 PM
Development and Application of a Multi-scale Simulation Toolkit to Model Fibrous Materials Properties: Adnan Taqi1; Matthew Beck1; 1University of Kentucky
Fibrous materials are used in thermal protection systems (TPS) for atmospheric entry of spacecrafts. Utilizing accurate models in the design of TPS to capture the physical processes result in higher accuracy and lower safety margins. To model the fibrous materials, representative volume elements (RVEs) are used to generate random micro-structure geometry whose mechanical properties, such as the elastic and bulk moduli, are then computed using the finite element method. The present work involves advancing the pre-processing and solver capabilities of the existing toolkit by incorporating new computational tools based on the finite element method and applying it to study the effects of parameters such as the ligament connectivity and orientations. The work makes it possible to better understand the relationships between the structure, processing and properties of fibrous materials.
2:40 PM
Investigating the Effect of the Aspect Ratio on the Elasticity of a Porous Material: Naji Mashrafi1; Matthew Beck1; 1University of Kentucky
As porous materials are studied, it becomes important to comprehend how the construction of the model representative volume elements (mRVEs) affects the overall elasticity. One of the main construction’s parameters is aspect ratio. When an mRVE is constructed from a seed geometry of spheres and conical frustums, the aspect ratio is defined as the height of a conical frustrum over the average diameter of the ligaments. This study aims to observe how the elasticity of the mRVEs are affected as a function of the aspect ratio. It was found that as the aspect ratio increases, the elasticity decreases.
3:00 PM
Scalable Metamaterial Synthesis via Colloidal Assembly: Bradley Straka1; Haydn Wadley1; 1The University of Virginia
A colloidal crystal is a porous metamaterial comprised of three-dimensional ordered arrays of similar size particles. Colloidal crystals are of interest to the scientific community because depending on particle shape, composition, size, and ordering colloidal crystals can exhibit novel optical, thermal, mechanical, and electromagnetic properties. Additionally, their inverses, inverse colloidal crystals, are of interest as they can exhibit significant stiffness and strength. In this work the scalable synthesis of colloidal crystals and their inverses via vibration induced colloidal assembly from powders and colloidal suspension of spheres from the millimeter scale to the nanometer scale is explored. How vibration parameters such as frequency, amplitude, and duration effect the ordering of the spheres is determined through models and experimentation in order to optimize the growth of large single crystal colloidal crystals suitable for industrial use.